For studies and references see the Harborview Injury Prevention Center's summary of helmet effectiveness studies if it is available. Otherwise, We have a page up linking to many helmet studies.Negative assertions are in bold italics below, followed by our responses. They fall into two categories: helmet laws and helmets themselves.
Opposition to Helmet LawsWe consider anti-helmet law views as legitimate and rational positions in the spectrum of political viewpoints. We do not consider ourselves "better than" those who oppose the laws, or even better qualified to make public policy, for which every citizen in a democracy is equally qualified.
Response: In some areas laws are being introduced before there is a popular consensus that bicycle helmets are an essential safety requirement. But the laws raise awareness that helmets save lives. We have laws here requiring seat belts, air bags, child car seats, smoke detectors, lights on bicycles operated at night, and a whole range of other safety devices. When a bicycle is a vehicle operated on a public roadway its operator is subject to the same rights and obligations as other vehicle operators. If it is reasonable to require motorcycle helmets, airbags and the use of car seatbelts, requiring bicycle helmets is also reasonable. If you see helmets as needed safety equipment rather than optional cycling apparel, the need for legal requirements is as apparent as the need to require lights on a bicycle operated at night. Back to top
Response: If true, this would be a serious drawback of helmet laws. Anyone who has observed the difference in riding in a city or country with many, many bicycles on the road understands how increasing the number of riders improves safety.
The cyclic trend reducing bicycle use that began here in 1999 was related to fashion, to the rise of other forms of exercise and to safety concerns as car traffic was becoming worse. We had a decade of experience prior to that with states and cities passing helmet laws, and did not observe declines in cycling related to the laws. The decline that did take place was not limited to the areas that had helmet laws, and the subsequent recovery in cycling and sharp rise in bicycle use when gas prices spiked in 2008 was not related to helmet laws either. In urban areas there has been a change in the attitudes of parents, who are concerned about traffic and crimes against children, and no longer allow their children the freedom to roam that bicycling used to facilitate. In addition, our helmet laws are so spottily enforced in most states that there would have been minimal effect in any case. In the last ten years the cycle has reversed. The current boom in bicycles for both transportation and sport use has coincided with trends in urban living, changes in attitudes toward car ownership, emphasis on fitness and improvements in bicycle facilities. All of this growth in bicycling in the U.S. has occurred in the presence of the bicycle helmet laws passed between 1987 and 2010, most of them not including adults.
Cost is not much of an obstacle to acquiring a helmet here, since our market supplies helmets at very low prices. We require seatbelts here in most of our states, but drivers do not stop driving because of that requirement. People do not move out of their homes to another state when smoke detectors are required by law. There is no statistical evidence that large numbers of motorcyclists quit riding in states that adopt mandatory motorcycle helmet laws, although it is certainly clear that some individuals in that group are extremely resentful.
On the other hand, the Swedish National Road and Transport Research Institute found indications that helmet laws can reduce cycling there in some age groups: see this abstract of their study for more info. But a research project in Toronto before and after their law came into effect showed that "although the number of child cyclists per hour was significantly different in different years, these differences could not be attributed to legislation. In 1996, the year after legislation came into effect, average cycling levels were higher (6.84 cyclists per hour) than in 1995, the year before legislation (4.33 cyclists per hour)." We are convinced that the answer to the question will lie in observational studies, and most of them will be local.
In 2009 a paper published on the Web site of the University of California at Irvine's School of Education used statistical analysis of national data to reach the conclusion that helmet laws resulted in a ridership decline of 4 to 5 per cent in the age group they covered. They do not seem to have realized that cycling overall declined in the US during the measured period. The data was collected from parents in telephone conversations, and we don't think that method is valid for helmet use studies. They did not control for traffic increases or parents' crime concerns in the states with laws, and those included California, New York, Pennsylvania, Florida and others where traffic grew the most. And some states have many local laws instead of a state-level law, skewing the comparison. Fortunately, you can read the entire paper, titled Intended and Unintended Effects of Youth Bicycle Helmet Laws on the Web and judge for yourself.
A 2010 Canadian study showed that bicycle usage remained constant after helmet laws were adopted in two provinces.
Response: One Australian bike share program reported dismal results in its early stages, and many attributed that to their all-ages helmet law. But in the US there is a bike share program in Seattle that has resolved that problem by making helmets available at the bike share stations. See our Bike Share Page for more. Back to top
Response: The British Medical Association once took this point of view. Apparently they had thought that Brits would either ride bicycles or become couch potatoes. In 2004 they reversed themselves and issued a call for helmet laws there. That is not the case in the US, where cycling certainly contributes to the overall fitness level of the populace, but millions of others prefer running, walking, swimming, rollerblading, skateboarding, skiing, rowing, basketball, football, baseball, soccer, lacrosse, handball, squash, volleyball, climbing, equestrian sports, aerobics or combinations of a thousand other activities to keep fit. But if the number of riders on the road were reduced this would be a serious issue because it would make the roads less safe for bicycles. Fortunately that is not the case. Back to top
Response: If safety equipment is required for any activity it does figure in the perception of the dangers involved. But in the US we find that requiring seatbelts and airbags in cars has done almost nothing to convince our drivers that there may be some remote danger in driving a car on our roads. We passed laws to require the use of belts and added passive restraints as well, but our annual highway death toll is still nearly 34,000 souls. That level of danger has done nothing to curb the use of the automobile in our society. The perception of danger in cycling here is almost exclusively confined to the danger of riding in traffic. For that reason cyclists without helmets here often say "I just ride on trails, so I don't need one." We do not believe that a requirement to use a helmet reduces cycling mileage here any more than seatbelt laws reduce driving. Back to top
In Australia, bicycle helmets are mandatory in all states and territories. Compliance is high but varies by area, with some cities over 90% and rural areas much lower. In the State of Victoria cyclists' head injuries declined 41%. There were 36% fewer child riders on the road, immediately after the legislation passed, but perhaps more adult riders. Changes in ridership may or may not have been related to the passage of the laws, and the road culture in Australia is unique to that country. Injury reduction was below expectations, but still spectacular. Hospital data from Western Australia showed that the number of intracranial injuries was cut in half with increased helmet use, while head injuries were less serious, and hospital stays shorter. After more than a decade of experience with helmet laws there is no serious consideration in Australia of repealing their laws, although in 2011 a film maker in Brisbane produced this anti-helmet law video for an organization called helmetfreedom.org that hopes to repeal the Queensland law. For that side of the Australian argument, see their site or the links at the bottom of this page. But a recent study from Queensland's CARRS-Q has examined the issue thoroughly from the bottom up, and concluded: "Current bicycle helmet wearing rates are halving the number of head injuries experienced by Queensland cyclists. This is consistent with published evidence that mandatory bicycle helmet wearing legislation has prevented injuries and deaths from head injuries. It is reasonably clear that it discouraged people from cycling twenty years ago when it was first introduced. Having been in place for that length of time in Queensland and throughout most of Australia, there is little evidence that it continues to discourage cycling. There is little evidence that there is a large body of people who would take up cycling if the legislation was changed." In 2013 the report of a Queensland parliamentary committee ignored this finding and recommended a trial suspension of the helmet rule for those 16 and over riding on trails and low speed roads, or using bikeshare program bicycles. Back to top
We have a page up linking to many studies that have concluded that helmet laws do increase the use of helmets. Back to top
Response: Many attempts we have seen in the U.S. to measure helmet effectiveness or helmet use nationally based on general statistics of bicycles on the road or rider surveys are indeed not useful. Anyone who has worked with bike riders in this country would not ask the question "How much did you ride last year" and expect a valid answer. Exposure data calculated from such surveys, including the survey by CPSC, are not in our opinion valid. The New York Times published an article in 2001 written by a reporter who missed that point, and reached some startling -- and invalid -- conclusions. We have a page up on that article. But we do consider valid a number of clinically-based studies in the U.S. on helmet effectiveness. We have parts of several of them included in our statistics page, including the landmark study by Thompson, Rivera and Thompson done at Harborview Injury Prevention Center and published in the New England Journal of Medicine in 1989. The same team completed another study that adds helmet analysis to the clinical data. You can find it on the Snell Foundation Web site. The study is old, but helmets sold in the US have actually improved since the data was collected, so we regard the conclusions as still valid and probably conservative. More importantly, the protective effect of helmets has been demonstrated in the field so thoroughly over a period of decades that statistical analysis based on poorly gathered data adds nothing to the knowledge base. Back to top
Although other studies have found lesser effects, this one remains close to the reality that club cyclists observe. Here is the abstract for a fine article about misunderstandings of the nature of case control studies and misinterpretations of their data that the authors noted in email exchanges. The authors are probably the most misunderstood and misinterpreted in the helmet field: the Drs. Thompson and Rivara. You have to pay to read the whole article, but the journal says it is one of their most popular downloads. For alternative numbers, see the SWOV paper above. When we refer to specific numbers, BHSI now quotes this 2009 study by the same authors showing that "helmets provide a 68% to 88% reduction in the risk of head, brain and severe brain injury for all ages of bicyclists. BHSI's parent organization, the Washington Area Bicyclist Association, has asked Federal agencies under the Data Quality Act to correct their use of the often-cited 85% number. Back to top
Response: The US now has the most concerted effort to improve bicycling safety in our history. There are more safety advocates here pushing for better cycling facilities (on or off road), cycling education, bike share programs and safer bikes themselves than at any other time in cycling's century-plus here. Every state department of transportation and many local governments have bicycle coordinators whose main focus is on improving bicycling conditions. Their activities sometimes extend to motorist education, where we bicycle questions appear now on drivers' permit exams. Our Federal government is funding bicycle transportation improvements of all kinds through transportation funding with millions of dollars at an unprecedented rate. In 2010 the Secretary of Transportation declared that bicyclists and pedestrians would get equal treatment with car drivers in Federal programs. The Federal Department of Transportation has produced helmet and bicycle safety materials and among other bicycle safety initiatives has sponsored development of a National Bicycle Safety Education Curriculum. The League of American Bicyclists kicked off in 1999 its most comprehensive safety initiative in more than 100 years of operation, and in 2007 proposed the development of a national bicycle strategy. The association that coordinates state traffic laws and safety standards in the US (AASHTO) has produced for the first time in its history a complete traffic engineer's handbook devoted only to standards for bicycle facility construction. All of this activity has been reinforced by the effort of many US cities to make their city safer and more attractive for bicycling and walking.
Although cycling organizations here had been trying to produce results like that for more than a century without success, the growth of these activities has occurred here concurrently with the growth of helmet promotion and use. The U.S. experience has demonstrated that blurred focus is not a problem here.
The fact remains that despite everyone's best efforts to make cycling as safe as it can possibly be, there will still be crashes, and without helmets there will still be an unacceptably high rate of head injuries, and given our conditions and riders, helmets will still be necessary here in the U.S. even if we can achieve the safest of cycling environments. Back to top
Response: Bicycle helmets and helmet laws are a rational response to a problem. Helmets may or may not be sensible in other activities such as motorcycling, skydiving, kayaking, horseback riding, skating, construction work, American football, baseball, hockey or driving a car. There is risky behavior of all kinds we are not addressing adequately, with people killed in the U.S. every year by lightning strikes at swimming pools and golf courses, or by fires in homes without working smoke detectors, or by carbon monoxide poisoning or by heart attacks brought on by smoking and lack of exercise. It is not necessary to optimize the entire world's injury prevention culture to appreciate the injury reduction that can be achieved in the U.S. with bicycle helmets. Back to top
Criticism of Helmets
Response: We have never found this to be the case. Bike helmets do not affect vision. If the helmet intrudes on upward vision it will be evident to the user, who can adjust the tilt of the helmet to raise the front lip. Bike helmets also do not affect hearing, since normally they do not cover the ears. That question is easily settled by riding with and without a helmet, or by standing beside a road with helmet on and off. The US DOT has conducted a study on this question using motorcycle helmets and found that even these larger helmets with additional coverage do not affect hearing, and have little effect on vision. Back to top
Response: This is a subjective judgment for each individual, and is easily tested by the user. Most riders find today's helmets light, comfortable and cool enough. Back to top
Response: Putting a helmet on takes less time than putting on bike gloves, but it does add another step every time you get on the bike, and we agree that it can be a nuisance on very short trips from one store to another. So is fastening your seat belt in a car, but you do it for safety. The helmet can be left with the bike, locked if the bike needs to be locked in that location. Back to top
Response: We have ample evidence from medical studies that helmets are indeed highly effective, and you will find references on our statistics page and our Journals page. Although bicycle helmets are tested in labs in impacts at 14 miles per hour, they usually do a fine job of protecting the rider in a crash where the initial forward speed is higher, because the severity of the impact is normally determined by the closing speed of the head and pavement, not by the rider's forward motion. Research on crashed helmets shows that most people hit the ground at a relative speed of about 10 MPH. If a rider is hit by a car or hits a brick wall at 30 mph and the head takes a direct blow at that speed, no helmet will prevent injury or death. But that type of crash is rare, and helmets are designed for the severity of the most frequent crash types.
As a reality check, ask any club cyclist about helmet effectiveness. They have shared experience that gives them more perspective on crashes. Club cyclists were the first to adopt helmets in the US, and the first to see the results. You will see helmets on all or most of the riders on virtually any club ride in the US. Among racers, the United States Cycling Federation (now USA Cycling--our road racing organization) adopted a mandatory helmet rule in 1986, because every year two or three riders were being killed in their races and more were suffering head injuries. In the years since it has been rare for a racer to die in a US race, even though their crashes occur at racing speeds. We have a page up on helmet protection limits. Back to top
Response: There is no consensus among the medical community on the threshold of rotational injury or how to measure it, although there is probably a rotational component in most serious head injuries. The standards-making community believes that a helmet that protects well against straight through (translational) impacts also reduces the effects of rotational injury, since most rotational motion comes from off-center translational impacts. But the damage to the interior of the brain is not simply a function of a turning motion. It results from different parts of the brain moving in different directions at different speeds after even a translational impact. Reducing the severity of the impact reduces that type of damage.
There is potential for improvement of current helmets eventually when rotational injury is better understood and means of predicting it in a crash are developed and accepted. Because this is an area requiring further research it has always been an easy target for raising doubt about the performance of current helmets. But in fact current helmets are a long way from perfect in almost any respect, and this is just one element that can be improved. That does not negate the benefits of wearing today's helmets. They work very well despite their imperfections. Back to top
Here is our page on a 2006 study done in England of passing distances. We think that study did not prove that wearing a helmet makes you less safe, and the research has been discredited by others. Back to top
Response: We have not observed that phenomenon. Riders here were just as careless in the 1960's and earlier without helmets as they are today. We have never been able to identify a case where a rider we knew began wearing a helmet and changed their risk-taking. The individual's perception of injury risk in a bicycle crash is generally not centered on their head, but on body parts. Most riders do not consider the head the most vulnerable part of the body. They are primarily concerned with the road rash and broken bones that are much more frequent than brain injuries. Helmets do not change those risks. Many motorcycle riders here who reject helmets still use leather clothing for skid protection. Once accustomed to a helmet, riding without it does make the rider feel vulnerable - - for the first half mile. Similar effects can be seen with seat belts, where the risk compensation argument also was used at one time, and even anti-lock brakes and airbags have been accused of making car drivers more aggressive. We think there may be a few who would smoke in bed more if they installed a smoke detector in their house, but not many. In 2011 this Norwegian study concluded that there are complex issues in determining how much risk compensation cyclists might do when they use helmets, but that "The use of [a] bicycle helmet as such does not seem to be related to either accident proneness or speeding." And a study published in Australia in 2013 concluded that unhelmeted riders were actually more likely to take risks like disobeying traffic controls or cycling while drunk. Back to top
Response: When the impact occurs, the helmet is between the head and the hard place, where weight is unimportant. If that were not the case, we would see an increase in head or neck injuries in helmeted riders, and that has not happened. Motorcycle helmets are much heavier than bicycle helmets, and if there were a tendency for helmet weight to be a factor it would have shown up there. Under normal riding conditions, the weight of a helmet does not destabilize the rider. Competitors in BMX competitions with three pound motorcycle helmets on their heads maintain amazing balance despite difficult track conditions and jumps. In 2011, a published study confirmed that motorcycle helmets do not injure necks. A helmet does have a larger diameter than the head. But it would be more accurate to say that the helmet might increase the likelihood of hitting the helmet itself, not the head. Back to top
Response: Although polycarbonate is used in many helmet shells and some formulations of it are suspected as one of the sources of the chemical BPA in the environment, there is no evidence yet that the helmet shells pose any danger to the wearer. We are more concerned about materials used in the interior of the helmet in contact with the skin. See our page on plastics in helmets for more info. Back to top
Response: Like any piece of wearing apparel, you have a choice of cheap or expensive. In the US market, cheap helmets are $10 to $20 at the big-box discount stores like Wal-Mart and Target, and are just as protective as the more expensive ones. Under Five stores now have a $5 helmet. A study in New Zealand once suggested that helmets there were not cost-effective, but in the US the analysis prepared by Ted Miller of the Pacific Institute for Research & Evaluation in 2009 suggested that every dollar spent on bicycle helmets saves $15 for adults and $47 for children. Back to top
Response: Actually, some do, and increasingly parents are helmeting their children there, as evidenced by this report on helmet promotion by their Foundation for Consumer Safety. And there are calls for mandatory helmet laws for children and seniors. The cycling tradition is so ingrained in Dutch culture that most adults do not see any need for helmets, despite the injuries documented by the Foundation report. They benefit from uniquely safe bicycle facilities and drivers who are expecting them on the roads because they are so numerous and who must by law give them full right of way when appropriate. When compared to the US, there are significant differences in road design, road surfaces, trails, traffic, signalization, motorists' attitudes, cyclists' attitudes, legal consequences of a car/bike crash, the bicycles themselves, car lighting, bike lighting and accessories, climate, the type of riding people do, the normal uses they put bicycle to, the number of cyclists on the roads and a whole range of other factors. We would not tell the Dutch they need helmets, although we wear one when cycling there. But we would tell a US rider that we think you need one here. (For a view of what we need to be doing in the US to improve our road environment, check out this campaign, one that we have supported and have attempted to advance with very little success.) For a very lucid explanation of the Dutch view, see this SWOV paper on helmets and helmet effectiveness. It has some much lower estimates for the injuries helmets can prevent, but says their European helmets are not to be compared with the more protective US and Australian standard models. Back to top
Response: Developing countries usually have other problems that swamp their head injury problems, and there is not much info on the head injury rates. We have begun to see indications that there is a significant unpublicized problem in China, and as this article on Vietnam shows, other countries as well. In 2007 Vietnam adopted a stringent helmet law for motorcycle riders. The trend should continue as more countries can afford more motor vehicles, a factor that contributed to the Chinese problem. Back to top
Why we are not on the blogs, twitter or facebook.We are not helmet warriors. We don't clutter blogs and other social media with repetitive rhetoric and sterile rebuttals. We add to this page as new stuff comes to our attention. We have changed this page in response to good comments from those who do not agree, and will read anything you send us, whether or not we reply.
This site is specialized in helmets. We don't cover smoke detectors, seat belts, airbags, diet, exercise, or other beneficial stuff. But on our home page, right up front in the introduction, we put helmets in perspective as a secondary safety measure, and we never lose that perspective. When we see "straw man" assertions in a blog that we are blind helmet promoters, that we are all about helmet compulsion, or outright lies asserting that we accept funding support from the helmet industry, we judge the poster's other statements with those inaccuracies in mind.
No matter what you may read in a blog or other message, we do not and have never accepted funding from the helmet industry or anyone connected with the retailing of helmets. And we don't own stock in helmet companies. Anyone who says that is mistaken or deliberately lying. That should prompt you to question other assertions by the email's author.
We have seen some amazing misrepresentations of fact in helmet wars messages. We have seen many bloggers misquoting studies. Others base misleading or incorrect statements on illogical or misleading interpretations of a study whose authors actually reached different conclusions. We have seen seemingly authoritative statements about helmet standards that were just plain wrong, with specific numbers pulled out of thin air. (We have a standards comparison up if you need to check any of them.) In some cases guesses and opinion are stated as known fact, and on the Internet it may be difficult to judge the sender's competence or clarity of thought. That includes ours, of course, although the context of this Web site may provide more basis for understanding our biases and where we are coming from. Our conclusion is that the blogs and other media have proven a poor choice for discussion of helmet questions, and readers can find more accurate and better-organized information at Web sites, including the anti-helmet law sites below. This explains the reluctance of many social media users to get involved in the exchanges. Please note that this paragraph did not single out either side in the arguments as the primary transgressor.
The Other Side
This page was updated or partially revised on: March 16, 2016.